Mandarin Pork Roast

• 1 pork loin (boneless)
• 1 chicken flavored bouillon cube
• 1 onion (chopped)
• 120 ml water
• 60 ml vinegar
• 55 gr brown sugar (light)
• 45 gr green pepper (chopped)
• 30 ml dijon mustard
• 16 gr cornstarch
• 16 ml soy sauce